Etherified mercapto-methoxyamines

ABSTRACT

PROSTAGLANDINOXIMES, E.G. THOSE OF THE FORMULA   R1-S-C(-R2)(-R3)-N=R   R=9-DESOXO-PROSTAGLANDIN MOIETY R1=ALIPHATIC, ARALIPHATIC OR AROMATIC RADICAL R2,3=H OR R1, OR R2+R3=ALKYLENE ARE VALUABLE INTERMEDIATES IN THE PREPARATION OF PGE1 OR ANALOGS THEREOF.

United States A Patent 3,798,275 ETHERIFIED MERCAPTO-METHOXYAMINES Nebville Fig], West Orange, ard Isidoros Vlattas, Millurn, assi ors to iba-Gei Co oration Ardsley, N.Y. gy rp No Drawing. Filed Apr. 5, 1972, Ser. No. 241,423 Int. Cl. C07c 131/02 US. Cl. 260-609 R 3 Claims ABSTRACT OF THE DISCLOSURE Prostaglandinoximes, e.g. those of the formula R=9-desoxo-prostaglandin moiety R =aliphatic, araliphatic or aromatic radical R =H or R or R +R =alkylene are valuable intermediates in the preparation of PGE or analogs thereof.

BACKGROUND OF THE INVENTION It is known that B-hydroxy-ketones are labile products, prone to dehydration. This holds true for the prostaglandins (PG) of the E E and E; series, which easily dehydrate to the corresponding products of the A and B series, known to be biologically differently acting or much less active than the former.

Therefore, special protecting groups have been devised for the 0x0 group therein, as well as in precursors of these products, which prevent dehydration during synthetic manipulation, but allow the final regeneration of the desired ,B-hydroxyketone or any product obtainable therefrom.

Surprisingly, we have found new etherified mercaptomethoxyamines, which are sufliciently stable to handle and are extremely useful for said oxo-protecting purposes. Although said mercaptomethoxyamines contain two heteroatoms attached to a single, non-functionalized carbon atom and, therefore, would seem to be unstable, they turned out to be rather stable, sometimes even distillable hydroxylamine derivatives. They readily form oximes with either aldehydes or ketones, which are also rather stable in basic or moderately acidic media. They are cleaved, according to our new process, with mercuric salts in various media, to yield either the free oXo-compound directly, or the correspondingly etherified or esterified O-hydroxymethyloxime. The latter can either be hydrolyzed to the free oxime, or the aldehyde or ketone respectively, which latter step is illustrated in co-inventors Pat. No. 3,532,721.

SUMMARY OF THE INVENTION The present invention concerns and has for its object the provision of new etherified mercaptomethoxyamine compounds, more particularly of those corresponding to Formula I wherein R represents two hydrogen atoms or a 9-desoxoprostaglandin moiety or equivalent analog thereof, each of R R and R are identical or different lower aliphatic, cycloaliphatic, araliphatic or aromatic radicals, or R and R are hydrogen or lower alkylene, of methods for the preparation thereof, as well as of the new process which consists in reacting a compound of Formula I, wherein R is different from hydrogen, with a mercuric salt in an aqueous, alcoholic or acidic medium, hydrolyzing any resulting ether or ester of the formally drawn hemiacetal of Formula II in a more acidic or a basic medium and the presence or absence of a hydroxylamine acceptor, to yield R=O or the oxime thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The 9-desoxo-PGE moiety R, or the equivalent analog thereof, is preferably that of Formula III wherein each of R and R is hydrogen or lower alkyl, R is a lower aliphatic or cycloaliphatic radical and R is hydrogen, one metal equivalent or a lower aliphatic, cycloaliphatic, araliphatic or aromatic radical. The term lower referred to above and hereinafter in connection with organic radicals or compounds respectively, defines such with up to 7, preferably up to 4, carbon atoms.

Accordingly, a lower aliphatic radical R R R R and R represents preferably lower alkyl, e.g. methyl, ethyl, nor i-propyl, -butyl -pentyl, -hexyl or -heptyl; lower alkenyl, e.g. allyl or methallyl; or lower alkynyl, e.g. ethynyl or propargyl. Said lower cycloaliphatic radicals are preferably 3 to 7 ring-membered cycloalkyl, cycloalkenyl or (cycloalkyl or cycloalkenyl)-lower alkyl groups, e.g. cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl; cyclopent-l-enyl or cyclohex-l or 3-enyl; cyclopropylmethyl, cyclobutylmethyl, lor 2-cyclopentylethyl; cyclopent- 3-enylmethyl or cyclohex-l-enylmethyl. Said araliphatic or aromatic radicals are preferably isocyclic, monocyclic radicals, such as phenyl-lower alkyl or phenyl groups, unsubstituted or substituted in the aromatic ring by one or more than one, especially one or two, of the same or different substituents, such as lower alkyl, e.g. methyl, ethyl, nor i-propyl or -buty1, lower alkoxy, e.g. methoxy, ethoxy, nor i-propoxy or -butoxy, lower alkylenedioxy, e.g. methylenedioxy, 1,1- or 1,2-ethylenedioxy, halogeno, e.g. fiuoro, chloro, bromo or iodo, trifluoromethyl, nitro or amino, such as di-lower alkylamino, e.g. dimethylamino or diethylamino. Said aliphatic radicals, especially lower alkyl groups R can also be substituted by one of said lower alkoxy groups or one or up to the maximum num ber of halogen atoms, as is the case in trifluoromethyl, 2-(methoxy, ethoxy, chloro, bromo or iodo)-ethyl, -propyl or -butyl, 2,2-dichloro-ethyl, -propyl or -butyl, 3,3,3 trichloroethyl, 3-(methoxy, ethoxy, chloro or bromo)- propyl or -butyl, 4-(methoxy or chloro)-butyl. A lower alkylene group R +R is preferably ethylene 1,2- or 1,3- propylene, 1,2-, 1,3-, 1,4 or 2,3-butylene or 1,2-, 1,3-, 1,4-, 1,5-, 2,3- or 2,4-pentylene.

Preferred compounds of the invention are those of Formula I, in which R represents two hydrogen atoms or the radical of Formula III, each of R R and R7 is lower alkyl, lower alkenyl, lower alkynyl, 3 to 7 ring-membered cycloalkyl, cycloalkenyl or (cycloalkyl or cycloalkenyl)- lower alkyl, each of R and R are also Ph-C H wherein Ph is phenyl, (lower alkyl)-phenyl, (lower alkoxy)- phenyl, (lower alkylenedioxy)-phenyl, (halogeno)-phenyl, (trifiuoromethyl)-phenyl, (nitro)-phenyl or (di-lower alkylamino)-phenyl, and n is an integer from 0 to 4, R is also (lower alkoxy or halo)-lower alkyl and R also hydrogen, an alkali metal atom or one equivalent of an (III) 3 alkaline earth metal, each of R R R and R are hydrogen or lower alkyl, or R is Ph, or R +R are lower alkylene.

More preferred are those compounds of Formula I, wherein R represents two hydrogen atoms or the radical of Formula III, R is C H or Ph-c H wherein m is an integer from 1 to 4, Ph is phenyl, tolyl, anisyl, fluorophenyl or chlorophenyl, n is an integer from to 2, each of R R R and R are hydrogen or lower alkyl, or R +R are ethylene, 1,2- or 1,3-propylene, R is lower alkyl, lower alkoxyalkyl or perfluoro-lower alkyl and R is hydrogen, sodium, potassium or lower alkyl, advantageously R +R contain at least 4 carbon atoms.

Especially valuable are compounds of Formula I, wherein R represents two hydrogen atoms or the radical of Formula III, R is methyl, benzyl, a-phenethyl or phenyl, each of R R R and R is hydrogen or methyl or R +R are ethylene or 1,3-butylene, R is t-butyl, n-pentyl, 2-ethoxyethyl or trifluoromethyl and R is hydrogen, sodium, potassium or alkyl with up to 4 carbon atoms.

The compounds of Formula I, wherein R represents two hydrogen atoms and the other symbols have the meaning given above, are prepared according to the following formula scheme:

(R is precursor of R and not H wherein X is a halogen atom, preferably chloro. The base used in the second step (b) is preferably a tertiary nitrogen base, such as a tri-lower alkylamine, e.g. triethylamine, or an azacyclic aromatic base, e.g. pyridine or collidine, and the hydrazine used is preferably a hydrate, e.g. the monohydrate, thereof.

The process according to the present invention can be depicted as follows:

(e) I (R is not Hr) 1 2 n fiy 12,011

R,-o-o-o-N=R 34 Ba (VII) wherein Y is one anion equivalent of an inorganic or organic acid, preferably that of a mineral acid, such as a hydrohalic acid, e.g. hydrochloric or hydrobromic acid; sulfuric or perchloric acid; or an aliphatic, araliphatic or aromatic carboxylic or sulfonic acid, such as a lower alkanoic or aralkanoic acid, e.g. acetic, propionic, benzoic or phenylacetic acid, or a lower alkane or benzenesulfonic acid, e.g. methane, ethane, benzene or ptoluenesulfonic acid, and R is hydrogen, lower alkyl or the acyl radical or a carboxylic acid, e.g. such mentioned above, preferably lower alkanoyl, e.g. formyl, acetyl or propionyl. The processes according to item (d) are analogously carried out as described in Pat. No. 3,532,721, but using compounds of Formula VI instead of the Z- substituted ethoxy-amines described therein.

Accordingly, the reaction according to the invention can be carried out either stepwise o i case R8 s ydrogen, in a single step, leaving the compounds of Formula VII as a shortliving intermediate in the reaction mixture. In case R is different from hydrogen, said compounds can be isolated from moderately acidic medla, especially for purification purposes. They can be hydrolyzed either to the oxime R=N-OH or the 0x0 compound R: 0, depending on the pH of the aqueous medium chosen. At values over 7, for example in the presence of alkali metal hydroxides carbonates or bicarbonates, or the above-centioned nitrogen bases, said oxime is obtained, whereas at values under 7, such as in mildly acidic aqueous solutions down to pH=2 of the above-mentioned acids, preferably in the presence of a hydroxylamine acceptor, such as formaldehyde, acetone, levulinic or nitrous acid, the oxo compound R=O is liberated.

The above reaction steps are carried out according to standard methods, in the presence or absence of diluents, preferably such as are inert to reagents and are solvents thereof, of catalysts, condensing, neutralizing or buffering agents and/or inert atmospheres, at low temperatures, room temperature or elevated temperatures, e.g. the boiling point of the diluents used, at atmospheric, superatmospheric or reduced pressure.

Thus, for example, step (a) can be carried out in the absence of a diluent, as long as the reactants are liquids. Otherwise steps (a) as well as (b) and (c) are advantageously carried out in polar diluents, preferably ethers for (a) and (b) e.g. diethyl ether or tetrahydrofuran, and alcohols, such as lower alkanols for (c). Step (d) is advantageously carried out with acid addition salts of VI, such as those derived from inorganic or organic acids, e.g. those mentioned for Y in a liquid base or neutralizing agent respectively, such as the nitrogen bases mentioned above. The media in steps (e) and (f) have already been mentioned; for solubility purposes, however, the presence of lower alkanols, e.g. methanol, ethanol, n or i-propanol, is advantageous.

The compounds of the invention, including any new ketones R=O, so obtained and are mixtures of isomers, can be separated into single isomers by methods in themselves known. For example, stereomers can be separated by virtue of the physicochemical diiferences between the components, for example, by chromatography and/or fractional crystallization. Also racemic products, e.g. R=O, are resolved into optical antipodes in the usual manner, or according to the present invention by reacting 1t w1th a compound of Formula VI, containing a center of asymmetry, separating the diastereomers obtained according to the above separation methods, and liberating the optically active products according to the process mentioned under items (e) and (f).

The new ketones R=O, wherein R is that of Formula III, m which R R and R have the meaning given above, and R is tertiary lower alkyl, preferably t-butyl, lower alkoxyalkyl, preferably 2-ethoxyethyl, or halogeno-lower alkyl, such as perfiuorolower alkyl, preferably trichloromethyl, are new and also considered part of this invention. Sa1d compounds are prostaglandin-like smooth muscle contracting, hypotensive and luteolytic agents, useful in the dosage range known for the natural prostaglandins, for example, in the treatment or management of hypertension and fertility. They are also valuable intermediates of other preparations, preferably of pharmacologically useful products.

The starting material used is known [e.g. Pat. No. 3,532,721 or H. Bohme et al., Ann., 563, 54 (1949)] or can be prepared according to the methods illustrated in the examples therein.

The following examples illustrate the invention, and are not to be construed as being limitations thereon. If not otherwise stated, all evaporations are carried out under reduced pressure. Temperatures are given in degrees centigrade and the N.M.R. spectra are obtained from about 10% solutions in deuterochloroform at 60 mc./s. with Si(CH as zero.

EXAMPLE 1 To the mixture of 31.7 g. of chloromethyl-methylsulfide, 45.1 g. of N-hydroxyphthalimide and v500 m1. of tetrahydrofuran, the solution of 46 ml. of triethylamine in 90 ml. of tetrahydrofuran is added dropwise and the mixture refluxed for 48 hours. It is filtered, the filtrate evaporated and the residue taken up in methylene chloride. The solution is washed 4 times with aqueous potassium bicarbonate, dried, evaporated and the residue crystallized from diethyl ether, to yield the N-methylmercaptomethoxy-phthalimide, melting at 94-95 The mixture of 40 g. thereof, 9.42 g. of hydrazine hydrate, 9.2 ml. of water and 350 ml. of 95% aqueous ethanol is refluxed for 4 hours and allowed to cool to room temperature. It is filtered, the filtrate evaporated and the residue taken up in the minimum amount of diethyl ether. The solution is allowed to stand at 0 overnight, filtered, the filtrate evaporated, the residue distilled and the fraction boiling at 5455/ mm. Hg collected, to yield the methylmercaptomethoxyamine of the formula CH SCH ONH It is dissolved in the minimum amount of diethyl ether and the solution combined with ethereal hydrogen chloride until no further precipitate is formed. The mixture is filtered and the residue recrystallized from methanoldiethyl ether, to yield the methylmercaptomethoxyammonium chloride, melting at 149-151 with decomposition.

The mixture of 1.7 g. thereof, 3.2 g. of 2a-(6-methoxycarbonyl hexyl) 3-oxo-5a-trimethylsiloxy-cyclopentanecarboxylic acid methyl ester and 55 ml. of pyridine is stirred at room temperature overnight and evaporated. The residue is taken up in water, the mixture extracted with diethyl ether, the extract washed with water and 0.1 N hydrochloric acid, dried and evaporated. The residue is taken up in chloroform, the solution chromatographed on 100 g. of silica gel and the column eluted with chloroform-ethyl acetate (95:5), to yield the 2a-(6-methoxycarbonyl-hexyl) 3 methyl-mercaptomethoxyimino-5ahydroxy-cyclopentane-carboxylic acid methyl ester of the formula -c o 00H.

(CH1) fl-oooom matographed on 28 g. of silica gel and the column eluted with methylene chloride-ethyl acetate (9:1), to yield the 2B (6 methoxycarbonylhexyl) 3 methylmercaptomethoxyimino 5p hydroxy-cyclopentanecarboxylic acid methyl ester of the formula showing in the N.M.R. spectrum peaks at 4.38, 3.75 and 3.68 p.p.m.

The mixture of 0.765 g. thereof, 35 ml. of methylene chloride, 0.35 g. of dihydropyrane and 25 mg. of picric acid is allowed to stand at room temperature overnight and evaporated. The residue is taken up in diethyl ether, the solution washed with 10% aqueous potassium bicarbonate and water, dried and evaporated. The residue is chromatographed on silica gel and eluted with ethyl acetate-methylene chloride (1:9), to yield the ZB-(G-methoxycarbonyl hexyl) 3 methylmercaptomethoxyimino-Sfl- (2 tetrahydropyranyloxy) cyclopentane-carboxylic acid methyl ester, of the formula showing in the N.M.R. spectrum peaks at 3.74, 2.24 and 1.55 p.p.m.

To the solution of 0.9 g. thereof in 60 m1. of anhydrous ethanol, 1.8 g. of sodium borohydride are added portionwise and the mixture is stirred at room temperature for 2 hours. Additional 0.9 g. of sodium borohydride are added and the mixture stirred 2 hours longer. It is poured into ice water, the mixture extracted with diethyl ether, the extract dried and evaporated. The residue is chromatographed on silica gel and eluted with ethyl acetatemethylene chloride (3:7), to yield the 7/9-[2a-hydroxymethyl 3fl (Z-tetrahydropyranyloxy)-5-methylmercaptomethoxyimino-cyclopentyl]-heptanoic acid methyl ester of the formula 0 O U --cH,oH

(CHz)s-G 00011;

showing in the N.M.R. spectrum peaks at 5.14, 2.22, 1.62 and none at 3.74 p.p.m.

To the stirred mixture of 0.435 g. thereof, 12 ml. of dimethylsulfoxide and 12 ml. of benzene, 0.128 ml. of pyridine, 0.1 ml. of trifluoroacetic acid and 1.8 g. of 1-cyclohexyl-3-(2-morpholinoethyl)-carbodiirnide methop-toluene sulfonate are added in this order while stirring at 4. The mixture is allowed to stand for 24 hours at this temperature and poured into ice water. The mixture is extracted with diethyl ether, the extract washed with water, dried, filtered and evaporated, to yield the 25-(6- methoxycarbonyl hexyl) 3-methylmercaptomethoxyimino 5,8-(Z-tetrahydropyranylorq)-cyclopentane-carboxaldehyde of the formula "one -(orr.).ooooH.

om-s-om-oshowing in the N.M.R. spectrum peaks at 9.73, 3.67 and 1.38 p.p.m.

To the solution of 0.337 g. thereof in 40 ml. of diethyl ether, 0.49 g. of tri-n-butyl-phosphoranylidene-2-heptanone are added and the mixture stirred at room temperature overnight. It is evaporated, the residue chromatographed on silica gel and eluted with ethyl acetate-methyl ene chloride (1:9), to yield the 7fi-[Za-(3-OXO-I-H'8J1Sr octenyl) 3B-(Z-tetrahydropyranyloxy)-5-methylmercaptomethoxyimino-cyclopentyl]-heptanoic acid methyl ester of the formula H O I (g =ICCO(GH:)4CHa I H (CH )a-COOCHa CH3- S -CH3O showing in the N.M.R. spectrum peaks at 6.50, 2.24 and 0.90 ppm.

To the solution of 57 mg. thereof in 3 ml. of 95% aqueous ethanol, 0.1 g. of sodium borohydride are added, and the mixture is stirred under nitrogen for /2 hour at room temperature. It is diluted with ml. of diethyl ether, washed with water and saturated aqueous sodium chloride, dried, filtered and evaporated, to yield the 7p- [2u-(3g-hydroxy 1 trans-octenyl)-3B-(Z-tetrahydropyranyloxy)-5- methylmercaptomethoxyimino cyclopentyl] heptanoic acid methyl ester of the formula showing in the N.M.R. spectrum peaks at 5.20, 4.64 and 0.90 p.p.m.

To the solution of 60 mg. thereof in 1 ml. of methanol, 50 ,ul. of 2 N hydrochloric acid are added and the mixture stirred at room temperature overnight. It is diluted with 100 ml. of diethyl ether, washed with Water and saturated aqueous sodium chloride, dried, filtered and evaporated. The residue is subjected to preparative thin layer chromatography on silica gel plates (1 mm. thick), eluted twice with ethyl acetate-methylene chloride (3:7) and of the two main fractions the slower moving isomer is isolated, to yield the 75 [20:(3/8 hydroxy-l-trans-octenyl)-3,B-hy droxy 5 methylmercaptomethoxyimino cyclopentyl]- heptanoic acid methyl ester of the formula melting at 48-50.

To the solution of 82 mg. thereof in 5.7 ml. of acetic acid, 0.24 g. of potassium acetate are added, followed by 0.275 g. of mercuric chloride and 0.115 g. of mercuric oxide and the mixture is stirred at room temperature for /2 hour. It is diluted with acetone, hydrogen sulfide bubbled through, filtered and the residue washed with acetone. The filtrate is evaporated at room temperature, the residue taken up in water, the mixture extracted with diethyl ether, the extract dried and evaporated, to yield the 7p-[2a-(3 8- hydroxy 1-trans-octenyl)-3 ,B-hydroxy-S-acetoxymethoxyimino-cyclopentyl]-heptanoic acid methyl ester, showing in the N.M.R. spectrum peaks at 5.60, 3.67 and 2.10 ppm.

To the solution of 34 mg. thereof in 3 ml. of methanol, 0.5 ml. of 10% aqueous potassium carbonate are added and the mixture allowed to stand at room temperature for /2 hour. It is evaporated, the residue taken up in water, the mixture extracted with diethyl ether, the extract dried, evaporated and the residue crystallized from diethyl etherhexane, to yield the d,l-PGE methyl ester oxime melting at 105-107".

Variously to the solution of 68 mg. of 7,8-[2a-(3fi-hydroxy l-trans-octenyl)-3,B-hydroxy-Sracetoxymethoxyimino-cyclopentyl1-heptanoic acid methyl ester in 6.8 ml. of methanol, 1.13 ml. of 10% aqueous potassium carbonate are added and the solution allowed to stand at room temperature for 4 days. It is evaporated, the residue dissolved in 3.5 ml. of glacial acetic acid, and 1.5 m1. of 10% aqueous sodium nitrite are added at 10 while stirring. After 1 hour, the same amount of sodium nitrite is added and the mixture allowed to reach room temperature within 15 minutes. It is diluted with water, extracted with ethyl acetate-diethyl ether (3:1), the extract washed with saturated aqueous sodium chloride, dried and evaporated at room temperature. The residue is taken up in 0.2 ml. of ethyl acetate and the solution allowed to stand overnight at 50. The precipitate formed is separated and recrystallized from ethyl acetate, to yield d,l-PGE melting at 112-115.

EXAMPLE 2 The mixture of 63.4 g. of chloromethyl-phenylsulfide, 81.5 g. of N-hydroxyphthalimide, 49.6 g. of triethylamine and 830 m1. of tetrahydrofuran is refluxed for 15 hours. After cooling, it is filtered and the filtrate evaporated. The residue is taken up in methylene chloride, the mixture washed 5 times with 10% aqueous potassium bicarbonate and once with water, dried, evaporated and the residue crystallized from diethyl ether, to yield the N-phenyl-mercaptomethoxy-phthalimide, melting at 87- 88.5

The mixture of 75 g. thereof, 13.5 g. of hydrazine hydrate and 600 m1. of aqueous ethanol is refluxed for 4.5 hours and allowed to slowly cool to room temperature. The precipitate formed is filtered off, the filtrate evaporated and the residue taken up in the minimum amount of diethyl ether. The solution is cooled to 0, additional precipitate filtered off and the filtrate evaporated. The residue is distilled and the fraction boiling at 8487/0.1 mm. Hg collected, to yield the phenylmercaptomethoxyamine of the formula It is dissolved in the minimum amount of diethyl ether and the solution combined with ethereal hydrogen chloride until no further precipitate is formed. The mixture is filtered and the residue recrystallized from methanoldiethyl ether, to yield the phenylmercaptomethoxyammonium chloride, melting at -112 with decomposition.

The mixture of 2.05 g. thereof, 2.3 g. of 2a-(64methoxycarbonyl-heXyl)-3-oxo 5a hydroxy cyclopentane carboxylic acid methyl ester and 6 3 ml. of pyridine is stirred at room temperature overnight and evaporated at room temperature. The residue is taken up in water, the mixture extracted with diethyl ether, the extract washed with Water, 0.2 N hydrochloric acid and water, dried, evaporated and the residue crystallized from diethyl etherhexane, to yield the 2a-(6-methoxycarbonyl-hexyl)-3- phenylmercaptomethoxyimino 5a-hydroxy-cyclopentanecarboxylic acid methyl ester melting at 53-55.

7.0 g. thereof are added to the solution obtained from 250 ml. of methanol and 0.105 g. of sodium and the mixture is refluxed overnight under nitrogen. It is evaporated, the residue taken up in water, the mixture extracted with diethyl ether, the extract washed with water and saturated aqueous sodium chloride, dried, filtered and evaporated. The residue is chromatographed on 400 g. of silica gel and the column eluted with ethyl acetate-methylene chloride (5:95), to yield the 2j3-(6-methoxycarbonylhexyl)-3-phenylmercaptomethoxyimino 5,8 hydroxy cyclopentanecarboxylic acid methyl ester, showing in the N.M.R. spectrum peaks at 7.7-7.0, 5.45 and 4.35 ppm.

The mixture of 3.2 g. thereof, 210 ml. of methylene chloride, 2.1 ml. of dihydropyrane and 210 mg. of picric acid is allowed to stand at room temperature overnight and evaporated. The residue is taken up in diethyl ether, the solution washed 4 times with 10% aqueous potassium bicarbonate and once with water, dried and evaporated. The residue is chromatographed on 120 g. of silica gel and eluted with ethyl acetate-methylene chloride (1:9), to yield the 2 3-(6-methoxycarbonyl-hexyl)-3-phenylmercaptomethoxyimino-SB-(Z-tetrahydropyranyloxy) cyclo pentane-carboxylic acid methyl ester, showing in the N.M.R. spectrum peaks at 3.72, 3.66 and 1.62 p.p.m.

To the solution of 3.7 g. thereof in 200 ml. of ethanol, 4.0 g. of sodium borohydride are added at once and the mixture is stirred at room temperature for one hour. Additional 1.0 g. of sodium borohydride are added and the mixture stirred 3 hours longer. It is evaporated, the residue taken up in water, the mixture extracted with diethyl ether, the extract washed with cold water, dried and evaporated. The residue is chromatographed on silica gel and eluted with ethyl acetate-methylene chloride (3 :7), to yield the 7,8-[2a-hydroxymethyl-3fi-(2-tetrahydropyranyloxy)-5-phenylmercaptomethoxyimino cyclopentyl] heptanoic acid methyl ester, showing in the N.M.R. spectrum peaks at 3.67, 2.30, 1.35 and none at 3.72 ppm.

To the solution of 52 mg. thereof in 5 ml. of methylene chloride, 165 mg. of pyridine-chromium trioxide complex in 5 ml. of methylene chloride are added at once and the mixture stirred at room temperature for minutes. It is washed with water twice, dried, treated with charcoal, filtered and evaporated, to yield the 2fi-(6-methoxycarbonyl-hexyl)-3-phenylmercaptomethoxyimino 5B (2- tetrahydropyranyloxy cyclopentane carboxaldehyde, showing in the N.M.R. spectrum peaks at 9.75, 5.40 and 3.61 p.p.m.

To the solution of 0.405 g. thereof in 20 ml. of diethyl ether, 0.41 g. of tri-n-butyl-phosphoranylidene-Z-heptanone are added and the mixture stirred at room temperature overnight. It is evaporated, the residue chromatographed on silica gel and eluted with ethyl acetatemethylene chloride 1:9), to yield the 7fl-[2a-(3-oxo-ltrans-octenyl)-3}8-(2-tetrahydropyranyloxy) 5 phenylmercaptomethoxyimino cyclopentyl] heptanoic acid methyl ester, showing in the N.M.R. spectrum peaks at 9.75, 4.50 and 0.90 p.p.m.

To the solution of 0.425 g. thereof in 40 ml. of ethanol, 0.45 g. of sodium borohydride are added during 5 minutes and the mixture is stirred under nitrogen for /2 hour at room temperature. It is poured into ice water, extracted with diethyl ether, the extract washed with water and saturated aqueous sodium chloride, dried, filtered and evaporated, to yield the 7,8 [2a (3g hydroxy-1-trans octenyl 3,8 (2 tetrahydropyranyloxy)-5phenylmercaptomethoxyimino-cyclopentyl]-heptanoic acid methyl ester showing in the N.M.R. spectrum peaks at 5.60, 1.64 and 0.90 p.p.m.

To the solution of 0.425 g. thereof in 50 ml. of methanol, 0.2 ml. 1 N hydrochloric acid are added and the mixture allowed to stand at room temperature overnight. It is evaporated, the residue subjected ot preparative thin layer chromatography on silica gel plates (1 mm. thick), eluted twice with ethyl acetate-methylene chloride (3:7) and of the two main fractions the slower moving isomer is isolated, to yield the 75-[2a-(35-hydroxy-l-trans-octenyl)- 3fi-hydroxy-5-phenylmercaptomethoxyimino-cyclopentyl]- heptanoic acid methyl ester, melting at 52-54 after recrystallization from diethyl ether-hexane.

To the solution of 85 mg. thereof in 5.7 ml. of acetic acid, 238 mg. of potassium acetate are added, followed by 272 ml. of mercuric chloride and 113 mg. of mercuric oxide and the mixture is stirred at room temperature for /2 hour. It is diluted with acetone, hydrogen sulfide is bubbled through, filtered and the residue washed with acetone. The filtrate is evaporated at room temperature, the residue taken up in water, the mixture extracted with diethyl ether, the extract dried and evaporated, to yield the 718- [2a-(3fi-hydroxy-l-trans-octenyl)-3,8-hydroxy-5 acetoxymethoxy-imino-cyclopentyl]-heptanoic acid methyl ester, which is identical with that obtained according to Example 1.

The starting material is prepared as follows: To the solution of 6.09 g. of 2a-(6-methoxycarbony1-hexyl)-3- oxo-5a-trimethylsiloxy cyclopentane carboxylic acid methyl ester in 250 ml. of methanol, 1 ml. of formic acid is added and the mixture allowed to stand at room temperature overnight. It is evaporated and the residue crystallized from diethyl ether, to yield the 2a-(6-methoxycarbonyl-hexyl)-3-oxo-5a-hydr0xy-cyc10pentane carboxylic acid methyl ester, melting at 68-70".

EXAMPLE 3 Through the mixtureof 55.09 g. of thiophenol and 44 g. of acetaldehyde, anhydrous hydrogen chloride is bubbled for 3 hours at 15, 5 g. of calcium chloride are added and the mixture is allowed to stand at 0 for 2 hours. It is filtered, the residue washed with methylene chloride and the filtrate evaporated at room temperature, to yield the 1-chloroethyl-phenylsulfide.

To the mixture of 86 g. thereof, 97.8 g. of N-hydroxyphthalimide and 400 ml. of tetrahydrofuran, the solution of 58.6 g. of triethylamine in 100 ml. of tetrahydrofuran is added dropwise and the mixture refluxed for 15 hours. It is filtered cold, the filtrate concentrated, the concentrate diluted with methylene chloride and the mixture washed 6 times with 10% aqueous potassium bicarbonate, dried, evaporated and the residue crystallized from diethyl ether, to yield the N-(l-phenylmercaptoethoxy)-phthalimide, melting at 63-67.

The mixture of 20 g. thereof, 2.24 g. of hydrazine hydrate, 2.2 ml. of water and 200 ml. of aqueous is refluxed for 4 hours and allowed to cool to room temperature. It is filtered, the filtrate evaporated and the residue taken up in the minimum amount of diethyl ether. The solution is allowed to stand at 0 overnight, filtered, the filtrate evaporated, the residue distilled and the fraction boiling at 74-76/0.l mm. Hg collected, to yield the 1- phenylmercaptoethoxyamine of the formula CaH S'ZIIHNOHz CH:

In the analogous manner, the following compounds of Formula VI are prepared from equivalent amounts of the corresponding starting materials:

mm. Hg, phthalimide,

Number R R2 R3 degree degree 1. Benzyl H H 8689 102-103 2. do 3 H 72-74 3. H 1l7-119 Instead of using monomeric aldehydes, also polymers thereof can be applied, e.g. paraformaldehyde.

EXAMPLE 4 I (CH2) o-COOCH;

GaH5-S-CHr-O- 1 1 showing in the N.M.R. spectrum peaks at 7.7-6.5, .45 and 3.65 p.p.m.

To the solution of 365 mg. thereof in 35 ml. of ethanol, 0.4 g. of sodium borohydride are added during 5 minutes and the mixture is stirred for /2 hour at room temperature. It is poured into water, extracted with diethyl ether, the extract washed with water and saturated aqueous sodium chloride, dried, filtered and evaporated, to yield the 7,3- [2oc-(3-hydroxy-4,4-dimethyl-l-transpentenyl) 35 (2- tetrahydropyranyloxy)-5 phenylmercaptomethoxyiminocyclopentyl] -heptanoic acid methyl ester of the formula (CHDo-OOOCH;

C5H5SCHg-O- showing in N.M.R. spectrum peaks at 5.60, 2.20 and 1.60 ppm.

To the solution of 350 mg. thereof in 40 ml. of methanol, 0.15 ml. of 0.1 N hydrochloric acid are added and the mixture stirred at room temperature overnight. It is evaporated, the residue subjected to preparative thin layer chromatography on silica gel plates (1 mm. thick), eluted with ethyl acetate-methanol (1:1) and of the two main fractions the slower moving isomer is isolated, to yield the 7/3-[2a-(3fl-hydroxy-4,4-dimethyl-l-trans-pentenyl)-3'fl-hydroxy 5 phenylmercaptomethoxyimino-cyclopentyl] -heptanoic acid methyl ester of the formula showing in the N.M.R. spectrum peaks at 7.70-7.00, 5.60 and 3.65 p.p.m.

To the solution of 125 mg. thereof in 8.4 ml. of acetic acid, 355 mg. of potassium acetate are added, followed by 405 mg. of mercuric chloride and 355 mg. of mercuric oxide and the mixture is stirred at room temperature for A hour. It is diluted with acetone, hydogen sulfide bubbled through, filtered and the residue washed with acetone. The filtrate is evaporated at room temperature, the residue taken up in water, the mixture extracted with diethyl ether, the extract dried and evaporated, to yield the 7 fl-[2Ot-(3fl-hyd1'OXy 4,4-dimethyl-l-trans-pentenyl)- 3fl-hydroxy 5 acetoxymethoxyiminocyclopentyl]-heptanoic acid methyl ester, which is used as such without further purification.

To the solution of 95 mg. thereof in 9.5 ml. of methanol, 1.58 ml. of 10% aqueous potassium carbonate are added and the solution allowed to stand at room temperature for 4 days. It is evaporated, the residue dissloved in 5 ml. of glacial acetic acid, and 2 ml. of 10% aqueous sodium nitrite are added at 10 while stirring. After 1 hour, the same amount of sodium nitrite is added and the mixture allowed to reach room temperature within 15 minutes. 'It is diluted with Water, extracted with ethyl acetate-diethyl ether (3:1), the extract washed with saturated aqueous sodium chloride, dried and evaporated at room temperature. The residue is subjected to preparative thin layer chromatography on silica gel plates (1 mm. thick), eluted with benzene-dioxane-acetic acid (5:5: 0.25) and the main fraction with Rf==0.57 isolated, to yield the 7B-[2a-(3,B-hydroxy-4,4-dimethyl-l-trans-pen: tenyl)-3fi-hydroxy-5-oxo-cyclopentyl]-heptauoic acid of the formula HO H I (CHz)a-O O OH What is claimed is:

1. The etherified mercapto-methoxyamine of the formula wherein R is 3 to 7 ring-membered cycloalkyl, cycloalkenyl, (cycloalkyl or cycloalkenyl)-lower alkyl or Ph-C H wherein Ph is phenyl, (lower alkyl)-phenyl, (lower alkoxy)-phenyl, (halogeno)-phenyl, (trifiuoromethyl)-phenyl or (nitro)-phenyl and n is an integer from 0 to 4, R is hydrogen, lower alkyl or Ph, R is hydogen or lower alkyl or Ph, or R +R taken together are lower alkylene, or an acid addition salt thereof.

2. A compound as claimed in claim 1, in which formula R is Ph-C H wherein Ph is phenyl, tolyl, anisyl, fluorophenyl or chlorophenyl, n is an integer from 0 to 2, each of R and R are hydrogen or lower alkyl, or R +R are ethylene, 1,2- or 1,3-propylene, or an acid addition salt thereof.

3. A compound as claimed in claim 1, in which formula R is benzyl, a-phenethyl or phenyl, each of R and R is hydrogen'or methyl or R +R are ethylene or 1,3-butylene, or a hydrohalic acid addition salt thereof.

References Cited UNITED STATES PATENTS 3,280,225 10/ 1966 Barnas et a1. 260--583 DD 3,278,647 10/ 1966 Barnas et a1. 260583 DD FOREIGN PATENTS 956,914 5/ 1962 Great Britain 260583 DD,

LEWIS GOTTS, Primary Examiner D. R. PHILLIPS, Assistant Examiner US. Cl. X.R.

260468 R, 470, 514 R, 516, 583 DD 

